Shockproof X-ray unit



' Dec. 7, 1937, A, H. LAIDIG 2,10LM3 SHOCKPROOF' X-RAY UNIT Filed Deo. 5l, 1935 3 Sheets-Sheet l Dec. 7, 1937. A. H. LAIDIG ZJULMS SHOCKPROOF X-RAY UNIT Filed Dec. 3l, 1935 y 3 Sheets-Sheet 2 ATTORI Y ZJULM A. H. LAIDIG ec. 7, H937.

SHOCKPROOF X-RAY UNIT 5 Sheets-Sheet 3 Filed Dec. 3l, 1935 NN WN WM, nw.

Patented Dec. 7, 1937 UNITED STATES PATENT OFFICE assignments, to

Westinghouse Electric and Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application December 31, 1935, Serial No. 56,897

6 Claims.

My invention relates to X-ray apparatus and has particular reference to shockproof X-ray apparatus wherein the danger of accidental shocks resulting to a patient or operator are entirely eliminated and constitutes an improvement on the apparatus shown and described in the patent to Charles M. Slack and Alfred H. Laidig, No. 2,040,156 issued May 12, 1936 and assigned to the same assignee as the present invention.

As pointed out in this aforenoted copending application the most common type of shockproof X-ray apparatus at present utilized in the art is of the so-called oil immersed type wherein the X-ray tube and the high tension transformer for supplying the energy thereto are immersed ina' cooling and insulating material and encased in a metallic housing. Apparatus of the oil immersed type, however, has several inherent objectionable features due to the entire weight thereof which renders it exceptionally unwieldly and difficult to manipulate and the fact that the cooling and insulating medium acts as a iilter for the generated X-rays;

In the above noted copending application a shockproof unit is shown which obviates the undesirable features of the oil immersed type. Such unit comprises an X-ray tube having a foreshortened length than that normally required for a tube operating in air at the same applied voltage which is encased within a metallic housing. The energy for the tube is supplied by grounded metallic sheathed cables which are so connected to the recessed electrode terminals of the X-ray tube as to insulate the same and prevent spark over to grounded metallic parts of the' apparatus at the maximum operating voltages of the tube.

Also the grounded metallic sheathed cables extending from the isolated high voltage transformer act as bearings for the X-ray tube unit so as to enable the latter to be rotated about the axis formed by these cables to various inclinations. This enables the ready adjustment of the unit for the treatment of Various parts of the human anatomy or the radiographing thereof. VDue to the heat generated by the tube it is desirable that the anode be cooled in order to dissipate this heat. Accordingly it is usual to circulate a cooling and insulating medium interiorly or" the anode immediately in back of the target which receives the electron bombardment during operation of the tube. Such provision is shown in the above noted copending application wherein a cooling and insulating medium is circulated through conduits extending from a stutable reser- (Cl. Z50-35) voirv to the hollow anode stem. Such conduits are lprovided in addition to the high tension cables which renders the construction of the unit somewhat expensive.

It is accordingly the primary object of my present invention to provide a shockproof X-ray apparatus of the type shown in this copending application which is more economical to manufacture.

Another object of my invention is the provision of a shockproof X-ray apparatus wherein the X-ray tube and housing may be rotated about the grounded metallic sheathed cables to various inclinations and wherein a cooling and insulating medium is circulated through the hollow anode in order to cool the same and which medium flows through conduits or ducts forming an integral part of one of the grounded metallic sheathed cables.

Another object of my present invention is the provision of a shockproof X-ray apparatus wherein vthe unit may be rotated about the grounded metallic sheathed cables which supply the high potential energy for the tube and a cooling and insulating medium also flows through conduits provided in one of these cables for cooling of the anode during operation of the tube, with these conduits kforming an integral part of one of these cables, and provided with means which prevents collapsing of thel conduits and allows a uniform twist so as to facilitate rotation oi the unit about the grounded metallic sheathed cables to various inclinations without impeding the flow of the cooling medium.

Still further objects of my invention will become vobvious to those skilled in the art by reference to the accompanying drawings, wherein Figure'l is a side View of a shockproof unit constructed in accordance with my present invention. y

Fig. 2 is a side view on an enlarged scale partly in cross section and with parts thereof broken away. of the housing shown in Fig. 1.

Fig. 3 is an end View of the grounded metallic sheathed cable supplying the anode potential.

Fig. 4 is a view of the anode end of the X-ray tube constructed in accordance with my present invention.

Fig. 5 is an enlarged cross sectional view of the completed assembly with parts thereof broken away.

Fig. 6 is a sectional view of the assembly showing a diiierent angular position of the X-ray tube unit as shown in Fig. 5.

Fig. 7 is a cross. sectional view of the com- Fig. 8 isja sectional view taken on the line` VIII-VIII of Fig. 5.

Referring now to the drawings in detail I have shown in Fig'. 1 a shockproof X-ray unit constructed in accordance with my present invention wherein a metallic or other suitable ray opaque Y housing, such as shown generally at 5, encases an X-ray tube B, as shown in Figs. 4, 5, 6, '7 and 8, and prevents the egress of X-,rays except through a pervious window 'I. The X-ray tube 6 may be of any particular type, but preferably is of the construction Vshown and described more inv detail in the aforenoted copendingV application. More-V over, as hereinbefore stated my present invention constitutes an improvement on the construction 'shown in this copending application which is more or less confined to the construction of the anode end of the tube. The cathode terminal being identical to that fully shown and described in this copending application it is deemed unnecessary that further detailed description thereof be herein set forth.

The metallic housing is formed in sections to facilitate assembly of the tube therein and comprisesa center section 9l having the ray pervious window 'I and a suitable lining I0 of a metal 4of high atomic weight, such as lead, for shielding purposes. In order to prevent undue shocks to the tube a pair of cushion rings or the like, one

Y of which is shown at I2, may be carried by the center section which bears lightly against the envelope of the tube 8. End sections I3 both of which are substantially identical are arranged to overlap the center section 9 inthe Ymanner described in the aforenoted pending application. The end section I3 which surrounds the anode end of the X-ray tube is adapted to be secured to the center section by cap screws or the like I4 and is provided with an insulating sleeve I5 concentrically disposed and extending longitudinally thereof to well within the section. This sleeve is made an integral part of the housing by the provision of an annular shoulder I6 which is rigidly secured to the end of the section I3 by any suitable means, such as set screws or the like I'I.

A transverse notch I8 is provided at one end of the insulating sleeve I 5 for aligning the X-ray tube 8 with the ray pervious window, and the opposite end of the sleeve aligns with an opening provided in a flange portion I 9 extending outwardly from the section I3 and having a small recess for a purpose torbe hereinafter more fully described.

The grounded metallic sheathed cable 22 which extends from a suitable source of high potential electrical'energy (not shown) for supplying one side of this energy to the anode terminal is provided with a casing of insulating material 23, as shown in Fig. 3, which casing has a metal section at one end to be hereinafter more fully detailed. Surrounding the insulated sleeve 23 is an annular ring 24 which may be of any suitable material, such as cork, rubber, or the like, for the purpose of guiding the cable with its integral sleeve 23'interiorly of the insulated sleeve I5 carried by the housing. The opposite end of the` cable sleeve 23 is provided with a collar 25 having a recess 26 Vtherein which may be engaged by a suitable tool forrturning the cable as a unit when securing the same to the anode terminal ofthe X-ray tube.v At the same time a similar tool may be utilized which engages the l recess 2liV provided on the .casing shoulder IS to prevent the casing from rotating during assembly. Also to insurea tight fit between the flange portion ISV and the collar a combination of rubber and metal washers 2l are provided therebetween.

Referring to Fig. 4 it will be noted that the anode electrode immediately in back of the usual refractoryemetal target 28 is hollowV and near its open end is provided with/threads 29.

The periphery of the open end of the hollow Y anode stem is provided with laterally disposed sections 30 of increased thickness, as can be more readily'appreciated from Fig. 8, which itV into the notch I8 provided in the housing sleeve I5 to assure positioning of the X-ray tube 8 in the housing so that the target 28 aligns with the pervious window I to thus prevent displacement thereof and enable emission of X-rays through the window 1. Y

After assembly of the cable 22 together with its integral insulated sleeve 23,in the tube and housing the latter is grounded by means of Va metallic ange 32 which frictionally contacts the metallic sheathed portion of the cable 2.2and is secured to the section I3 in any suitable manner, such as by set screws or the like engaging tapped recesses 33. Thus when assembled the cables 22 together with the insulated sleeve 23 act as insulating means to prevent spark-over or the formation of coronabetween the high tension terminals and the grounded casing during operation of the tube.

In order to provide the cable 22 with its inte- 'gral sleeve 23, having the'v metal end, the metallic sheathing is first removed from the cable and an insulating sleeve 34 (Figs. 5, 6 and 7 )V of shorter length than the outer Ysleeve 23V is slipped over the rubber pcrtion'of the cable toform a snug rit. By reference more particularly to Fig. 5, it will be noted that the cable 22 is provided with an electrical conductor 35, which is connected to a recessed terminal 36 rigidly secured to the in'- sulating sleeve 34. Also a pair of conduits or ducts 31 and 38 are provided in the cable 22 through which a cooling and insulating medium such as oil or water is adapted to circulate forY These ducts 3Iv and 38V cooling the anode 28. protrude several inches beyond the extremity of the sleeve 34 and being of rubber or the like are of a exible nature.

Surrounding these conduits is a metallicrccvering 39 simulating a coil spring so as to prevent collapsing of the cables as well as cause uniform twisting thereof as the X-ray tube and housing are rotated as a unit about the cables, in the manner described in the aforementioned copending application.

A cylindrical metallic member 4l! having an increased diameter portion to form a shoulder 42 threadedly engages the end of the outer insulating cable sleeve 23 and after this connection isV made tight it is prevented from loosening by any suitable means, such as a set screwV 43. Itvwill be noted from Fig. 5 that the end of the insulating sleeve 23, which is threaded to engage this cylindrical member 4B, is slightly reduced in diameter so that upon engagement of the member 42 therewith the greatest diameter portionV of the member 4G is equal to the diameter of the sleeve 23. This accordingly forms a shoulder 44 interiorly of the sleeve 23 enabling it to be slid longitudinally of the inner sleeve 34 until such shoulder 44 contacts the end of the inner sleeve 34 permitting assembly of the remaining portions 0f the metallic end for the. cable 22.

An annular collar 45 having its outer periphery threaded and provided with recesses 4B for the engagement of a suitable tool is then slipped over the protruding ends of the iiexible conduits 31 and 38 with their metallic covering 39. Next a Washer 41, having suitable openings through which a pair of shouldered nipples 48 protrude and spaced apart so as to align with the flexible conduits 31 and 38, is placed over these latter conduits.

The free ends of the exible conduits are then slipped upon tapered projections 49 extending from a metallic member 58 'after which the washer 41 carrying the shouldered nipples 48 is moved toward the end of the flexible conduits and the collar 45 is then threadedly connected to this metallic member 50, by means of a suitable tool engaging the recesses 46, thus forcing the ends of the iiexible conduits 31 and 38 firmly over the projections 49 to form a fluid tight seal. For the purpose of establishing an electrical connection from the electrical conductor 35 the metallic member 5l! is additionally provided with a rod like extension 52 which slidably engages the terminal 36 rigidly secured to the inner insulating sleeve 34.

The metallic member 58 is next held stationary and the outer insulating sleeve 23 together with the cylindrical member carried thereby moved tothe left as viewed from Fig. 5 to separate the shoulder 44 from the end of the inner insulating sleeve 34. As the outer insulating sleeve 23 is provided with annular portions 53 which form suitable bearings it may be rotated .about the inner insulating sleeve 34 without twisting of the exible conduits 31 and 38 at this time intil a threaded connection is established between the cylindrical member and the metallic member 58. To complete the assembly of the metallic end for the cable 22 a cylindrical collar 54 having a flanged end 55 and a plurality of openings 56 is slippedover the metallic member and threadedly engages the smaller diameter portion of the cylindrical member 48.

When this latter connection is established the end of the cylindrical collar 54 will bear against the shoulder portion 42 of the cylindrical member 4l! and at the same time the flanged end 55 of the collar 54 will have seated in a peripherial groove 51 provided in the metallic member 5i). The cable 22 is thus provided with the sleeve 23 having the metallic end and forming an integral part of the cable as shown in Fig. 3 ready for connection to the unit comprising the X-ray tube 8 and housing. 5.

In assembling the complete unit the X-ray tube 8 is surrounded by the section I3 with the transverse notch I8 engaging the laterally disposed section 38 of the hollow anode stem to not only align the target 28 of the X-ray tube wi'th the window 1 when the center section 9 is joined to the anode end section I3, but also to relieve the X-ray tube from strain and in effect making the tube and housing an integral unit. The cable 22 with its integral insulating sleeve 23 and metal end is then passed through the opening providedA in the ange I9 along the insulating sleeve I5 and being guided by the annular ring 24 until the exteriorly threaded portion provided on the cylindrical member 48 forming part of the metallic end of the cable contacts the interiorly threaded portion 29 of the anode stem.

A suitable tool is then inserted in the recess 25 provided in the cable collar 25-and a similar tool inserted in the recess 20 of the flanged housing portion I9. While the unit may be held stationary and the cable turned it is preferable to reverse this operation to prevent twisting or 1ashing of the cable and screw the unit upon the cable.

Consequently the tool engaging the recess 28 is turned to rotate the unit, which causes no strain on the X-ray tube due to its forming an integral part of the housing through the connection of the slot I8 and the sections 30, and the tool engaging the recess 26 held stationary until the collar 25 together with washer 21 bears rmly against .the flanged housing portion I9. By this time the threaded portion of the cylindrical member 40 will have engaged the threaded portion 29 of the hollow anode stem to dispose the end of the member 58 a short distance in back of the anode head carrying the target 28. To ground the housing, as hereinbefore stated, the metallic ange 32 which frictionally engages the grounded metallic sheathed portion of the cable is secured to the flanged housing portion I9. The center section 9 of the housing is then secured to the anode end section I3 after which the cathode end section is secured thereto, as described in the aforementioned copending application, to thus complete the assembly of the entire apparatus as shown in Fig. 1.

In order to cool the anode during operation of the tube by the cooling and insulating medium supplied through the conduits 31 and 38, it will be noted by reference to Fig. 5, that the member 58 is provided with a longitudinal passageway 58 communicating with a lateral passageway 59 having an outlet concentric with a concave recess provided in the surface of the metallic member 58 adjacent the rear Wall of the anode head of the X-ray tube. This allows the fluid to flow from a reservoir or the like (not shown) through the conduit 31 and passageways 58 and 59 into contact with the rear surface of the anode head which is the area of greatest heat concentration.

'I'he cylindrical collar 54 being of lesser diameter than that of the interior of the hollow anode stem permits the fluid to circulate therebetween and due to convection currents it flows through the openings 56 provided in this collar. Due to the spacing between the collar 54 and the metallic member 50 an annular passageway 60 is formed which enables the fluid flowing through the openings 56 to flow around the member 50. This latter member is again provided with a passageway 82 communicating with the annular passageway 60 and lthe conduit 38 to permit the fluid to flow back to the reservoir for cooling.

During operation of the tube it is frequently necessary to rotate the unit to Various inclinations for treating or the taking of radiographs of various parts of the human anatomy. To accomplish this the operator need turn only vthe unit with the cables functioning as an axis for the rotation thereof. When the outer insulating sleeve 23 carrying the metal end portion .40 threadedly engages the hollow anode stem it in eiect thus becomes a part of the unit and necessarily rotates therewith about the inner sleeve 34 upon the bearings 53 with the inner sleeve 34 remaining stationary. This accordingly causes the iiexible portions of the conduits 31 and 38 to twist, as shown in Fig. 6, but owing to the metallic covering 39 provided thereon, such twist is not only maintained Auniform throughout the length of the flexing thereof, but this metallic covering prevents collapsing of the conduits', which 'would otherwise obstruct the iiowv of. the iiuid with a resulting building up of pressure and possible bursting of the conduits.

Moreover, it must be appreciated that rotation of the unit about the grounded metallic cables must be somewhat restricted to less than 360 to prevent complete twisting to such an extent as to obstruct the flow of the fluid.

To this end the inner sleeve 34 is provided with a peripheral groove 63 extending approximately 270 around its circumference, although it may be greater provided it is maintained less than a full 360, which is loosely engaged by a set screw or dowel pin 64 limiting its rotation but at the same time permitting slight longitudinal movement of the cable together with its integral insulated end.

It thus becomes obvious to those skilled in the art that I have provided a shockproof X-ray apparatus wherein the X-ray tube and housing may be rotated as a unit about the grounded metallic sheathed cables which supply the electrical energy to the tube and form an axial support for the unit. In addition a cooling and insulating medium is supplied through one of the grounded metallic sheathed cables which supplies the anode potential and the flexible conduits forming an integral part of this cable are s o connected to the anode as to uniformly twist without collapsing thereby preventing destruction of the iluid tight seal between the flexible conduits and the anode in any-axial position of the unit.

Although I have Shown and described one specific embodiment of my present invention I do not'desire to be limitedV thereto as various other modifications Ymay be made without departing from the spirit and scope of the invention as set forth in the appended Claims.

What is claimed: Y

1. A shockproof X-ray apparatus comprising an X-ray tube having an envelope provided with a thermionic cathode and an anode therein, electrode terminals for said anode and cathode, an X-ray opaque housing surrounding said X-ray tube and provided with a pervious window therein in alignment with the ray projecting portion of said X-ray tube, means forming an axial support for sai-d X-ray tube and housing to enable rotation thereof to various positions and connected to said housing andV X-ray tube for groundingV said housing to render the same shockproof and for supplying electrical energy to said'X-ray tube and a cooling and insulating medium to the anode thereof, and said means including flexible conduits integral with a portion of said means-and extending longitudinally thereof and forming a fluid-tight Seal with said anode terminal, and said means being axially lieldable interiorly of sai-d housing to enable said X-r'ay tube and housing to be rotated as a unit to various axial positions about said means without destroying the fluid-tight seal or collapsing and straining said flexible conduits.

2. A shockproof' X-ray apparatus comprising an X-ray tube having an envelope provided with Y oppositely disposed reentrant stems, electrode terminals carried by said envelope at the innermost extremities of said reentrant' stems,V an X-ray opaque Vmetallic housing surrounding said tube and provided with an X-ray pervious window in alignment With the ray projecting portion of said envelope, means connected to said housing to ground thelatter and provided with portions extending into said housing and connected to said electrode terminals for the purpose'of supplying electrical, energy thereto and for insulatingly supporting said X-ray tube and housing to enable rotation of said tube and Vhousing as a unit to various inclinations about said means and to prevent formation of corona or va discharge between said electroderterminals during operation of said tube, and said means being provided with a portion integral therewith and extending longitudinallyrthereof and forming a fluid-tight connection with one of said electrode terminals for circulatinga cooling and `insulating medium therethrough in Yall various inclinations of said X-ray tube and housing, and said integralV portion being axially yieldable interiorly of said housing to prevent collapse or straining thereof andrimpairing the circulation of the cooling and insulating medium.

3. A shockproof X-ray apparatus comprising an X-ray tube having an envelope provided with oppositely disposed reentrant stems, an anode and a cathode within said envelope and provided with electrode terminals disposed at the innermost extremity of said reentrant stems, an X-ray opaque Vmetallic housing surrounding said tube and provided with an X-ray perviouswindow in alignment With the ray projecting portion of said envelope, and means connected to said housing to ground the same and having portions thereof extending into the reentrant stems and connected to Vsaid electrode terminals for supplying electrical energy thereto and for insulatingly supporting said X-ray tube and housing to enable rotation thereof to various axial positions about said means, and said means including ilexible conduits forming a fluid-tight connection with the terminal for said anode for supplying a cooling and insulating medium to said anode in the various axial positions of said X-ray tube and housing relative to said meansand said iiexible conduits being axially yieldable interiorly of said housing to prevent collapse or straining thereof and impairing flow of said cooling and insulating medium. Y

4. A shockproof X-rayV apparatus comprising an X-ray tube having an envelope provided with a thermionic cathode and an anode therein, electrode terminals for said anode and cathode, an X-ray opaque housing surrounding said X-ray tube and provided with a pervious window therein in alignment with the ray projecting portion of said X-ray tube, a pair of grounded metallic sheathed cables forming an axial support for said X-ray tube and housing, said housing and X-ray tube being rotatable as a unit about said cables to various positions, and said cables being connected to said housing and X-ray tube for grounding said housing to render it shockproof and for supplying electrical energy to said X-ray tube, and one of said cables being provided with conduits integral therewith for circulating a cooling and insulating medium through the anode of said X-ray tube and having a flexible portion forming a fluid-tight seal with said anode terminal and axially yieldable interiorly of said housing to enable said X-ray tube and housing to be rotated to various axial Vpositions without destroying the fluid-tight seal or causing collapsing or straining of the flexible portion of one of said cables, thereby preventing impairment of the flo-w of the cooling insulating medium.

5. A shockproof X-ray apparatus comp-rising an X-ray tube having an'e'nvelope provided With a thermionic cathode and an anode therein, electrode terminals for said anode and cathode, an X-ray opaque housing surrounding said X-ray tube and provided with a pervious window therein in alignment with the ray projecting portion of said X-ray tube, a pair of grounded metallic sheathed cables forming an axial support for said X-ray tube and housing, said housing and X-ray tube being rotatable as a unit about said cables to various positions, and said cables being connected to said housing and X-ray tube for grounding said housing to render it shockproof and for supplying electrical energy to said X-ray tube, one of said cables having conduits integral therewith and provided with a ilexible portion forming a fluid-tight seal with said anode terminal for supplying a cooling and insulating medium thereto, and axially yieldab-le interiorly of said housing upon rotation of said X-ray tube and housing to prevent disruption of the luid-tight seal or straining and collapsing of said conduits in the various axial positions of said X-ray tube and housing, thereby preventing impairment to the flow of said cooling and insulating material.

6. A shockproof X-ray apparatus comprising an X-ray tube having an envelope provided with a thermionic cathode and an anode therein, electrode terminals for said anode and cathode, an

X-ray opaque housing surrounding said X-ray tube and provided with a pervious Window therein in alignment with the ray projecting portion of said X-ray tube, a pair of grounded metallic sheathed cables forming an axial support for said X-ray tube and housing, said housing and X-ray tube being rotatable as a unit about said cables to various positions, and said cables being connected to said housing and X-ray tube for grounding said housing to render it shockproof and for supplying electrical energy tosaid X-ray tube, one of said cables having conduits integral therewith and provided with a ilexible portion forming a fluid-tight seal with said anode terminal for supplying a cooling and insulating medium thereto and adapted to twist interiorly of said housing upon rotation of said X-ray tube and housing to prevent disruption of the uidtight seal or straining of said conduits in any axial position of said X-ray tube and housing, and a flexible metallic covering carried by the exible portion of said conduits interiorly of said housing to provide uniform twisting and prevent collapsing thereof upon rotation of said X-ray tube and housing toV their various axial positions.

.ALFRED H. LAIDIG. 

